This invention relates to a creel of the type which includes a twisting mechanism.
Conventionally, in producing various belt-formed textile fabrics such as safety belts, one of three methods is selectively employed including a method that a required number of warp yarns wound on a beam are used to weave a textile fabric therewith, another method that twisted yarns wound on bobbins mounted on a creel are supplied from the creel as warp yarns to a weaving machine, and a further method that untwisted yarns (filament yarns) wound on bobbins mounted on a creel are supplied from the creel as warp yarns as they are to a weaving machine is employed.
Of the methods described above, the second method wherein twisted yarns are used as warp yarns for weaving has following problems. In particular, twisting of yarns is not normally conducted by a textile fabric maker but is conducted by an external twisting manufacturer at a request of such a textile fabric maker, and although it is sometimes necessary to change the degree of twist of yarns in accordance with an appearance required for an intended textile fabric, it is inconveniently impossible to change the degree of twist in the course of a weaving process. Further, twisted yarns wound on individual bobbins may not always be of the same length and may vary in length, and in such a case, the twisted yarns may be partly wasted. Besides, twisted yarns wound on bobbins are normally greater in length than raw yarns on large packages, and accordingly time must be taken to splice twisted yarns to each other in the course of a weaving process and such spliced portions of twisted yarns will make a product which is partly bad at a portion thereof containing such spliced portions which must be abandoned. In addition, there are disadvantages that a rewinding step after twisting of yarns and, where warp yarns are to be wound on a beam, a warping step are required, and that the operability is low due to distortion of twisted yarns caused by untwisting of the same, and so on.
Meanwhile, in case untwisted yarns are supplied as warp yarns from a creel directly for weaving, because raw yarns of large packages are used as they are, little time is required to splice such raw yarns to each other in the course of a weaving process, and a rewinding step and a warping step are unnecessary and besides there is no necessity of sending raw yarns to a twisting manufacturer in order to have such raw yarns twisted by the manufacturer. From those reasons, the efficiency in production is very high comparing with the former method described above. However, products have some defects in quality such that they are also limited in appearance and are low in resiliency and in wear resistance. Further, since yarns are not in a twisted state during weaving, filaments of such yarns will not be bundled together well so that the yarns may be broken and fluffed readily. Accordingly, in worst cases, the weaving machine may have to be stopped in order to restore the machine to its normal running condition.
In order to resolve the problems described above, the applicant has proposed in Japanese patent application No. 57-029084 a creel which comprises a twisting mechanism provided for each of a bobbin on which an untwisted yarn is wound whereby the untwisted yarns are delivered from the bobbins to a weaving machine while they are being twisted at a same time.
According to the proposed creel, a relatively complicate mechanism similar to a flyer mechanism is employed for the twisting mechanism. This results in high cost of equipment because such a twisting mechanism is provided for each of a large number of bobbins on a creel, and for example where two seat belts are woven at a same time, about 600 to 700 bobbins are provided for a single creel. Accordingly, provision of such a large number of twisting mechanisms is not practical. Rather, use of twisted yarns is more practical so far as the workability and the cost are concerned.